Selective reduction of cysteine-engineered antibodies

Abstract

The present invention relates to a process for the selective reduction of cysteine-engineered antibodies comprising reacting an antibody comprising one or more engineered cysteines at positions selected from HC40, HC41,HC42, HC89, HC152, HC153, HC155, HC171, LC40, LC41, LC165, and LC168 with a compound according to formula (I), (II), (III), (IV), (V), (VI) or (VII): (I) (II) (III) (IV) (V) (VI) (VII), and to a process for the preparation of antibody conjugates, including antibody-drug conjugates (ADCs).

Description

FIELD OF THE INVENTION[0001]The present invention relates to a process for the selective reduction of cysteine-engineered antibodies and to a process for the preparation of antibody conjugates including antibody-drug conjugates (ADCs).BACKGROUND OF THE INVENTION[0002]Cysteine-engineered antibodies are increasingly used for conjugation of a therapeutic moiety (e.g. a drug or toxin), a radiopharmaceutical, a fluorescent label or a hydrophilic polymer. The introduction of a cysteine residue at a suitable position of the antibody allows control of the site of conjugation and the obtained site-specific conjugates are more homogeneous than the conjugates obtained via wild-type conjugation, i.e. conjugation via interchain disulfide cysteines. Such wild-type conjugation leads to a heterogeneous mixture of conjugates, which is especially disadvantageous in the case of ADCs. Some individual constituents of a wild-type conjugated ADC mixture can have poor in vivo performance. The in vivo perfo...

AI Technical Summary

Benefits of technology

This patent describes a way to make a specific type of antibody that can be used to treat cancer. The process uses a chemical called a reducing agent to change certain parts of the antibody. This change makes it easier to attach other chemicals to the antibody, such as drugs. This patent also provides a way to make drugs that can be attached to the antibody. Overall, this invention helps to create better ways to make antibodies and their drug conjugates, which can improve the treatment of cancer and other diseases.

Problems solved by technology

Such wild-type conjugation leads to a heterogeneous mixture of conjugates, which is especially disadvantageous in the case of ADCs.

Some individual constituents of a wild-type conjugated ADC mixture can have poor in vivo performance.

This common practice in protein modification is more complicated in an antibody because of the various native cysteine residues already present.

Introducing the extra cysteine residue in an unsuitable position could result inter alia in improper formation of interchain disulfide bonds and therefore improper folding of the antibody.

However, this conventional approach has several disadvantages.

Moreover, DHAA is instable in water, which complicates the mild re-oxidation process.

This solution, however, is disadvantageous as it requires a considerable modification of the standard equipment for drug conjugation.

However, the present inventors found that TPPTS reduces the interchain disulfide bonds of monoclonal antibodies, concluding that it is not a suitable agent for the selective reduction of engineered cysteines in monoclonal antibodies.

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